How many reps will he get during offfseason practices? How will preseason snaps be divided? Tolzien said he’s drawing on his college experience while following Jim Harbaugh’s just-get-better-every-day advice.

“Coach is always saying ‘Work and don’t worry,’” Tolzien said. “That’s just the way I’m trying to approach it. That’s the best way to approach it. I was in the same position in college and it doesn’t do you any good to measure yourself against the other guy on a day-to-day basis.”

Of course, a key difference between now and college is that Tolzien’s competition is no longer Dustin Sherer and Curt Phillips, the quarterbacks he beat out in 2009. Tolzien’s chances of supplanting Johnson or Kaepernick appear remote, but he’s earned the confidence of Harbaugh, who believes each of the 49ers’ quarterbacks will have extended NFL careers.

Tolzien, who doesn’t possess a huge arm, is known for his smarts and work ethic. Asked today about his plans for his time off before training camp, Tolzien said he’s been too focused on OTAs to think about vacation time. Last year, after he was signed by the 49ers, he initially slept in the players’ lounge and immersed himself in the playbook.

His diligence paid off at Wisconsin, where he set school records for career completion percentage (68.1) and quarterback rating (153.2) while leading the Badgers to the Rose Bowl as a senior.

His gym-rat mentality appeals to Harbaugh, who was struck by his work ethic at last year’s combine.

“I liked him when I went to the combine and there was nobody out on the field yet, but he came out early and was out there throwing the ball around,” Harbaugh said in September. “… He was always the first one out of the locker room just throwing balls, must have been for four to five hours. That’s what I noticed first, what I first noticed, first really liked.”

Tolzien has practice-squad eligibility – he was on the 53-man roster but inactive for every game last year – and he figures to attract suitors if he doesn’t survive final roster cuts. Tolzien said his focus is on improving and, to that end, he picks the brains of his competition. After practice today, he was chatting with Smith and Johnson as they lifted weights together.

“A lot of times, we’re discussing plays from the practice,” Tolzien said. “What was your thought on this play? What was the look we were getting? … We’re all professionals and we’re all trying to learn from one another. Shoot, some rep that Alex had, who knows — I might have that same play tomorrow so I want to learn from what he saw on it so I can maximize my rep.”

* Tolzien, then with the Chargers, has fond memories of last year’s preseason finale against the 49ers when he completed 16 of 23 passes for 226 yards with a touchdown and an interception.

He also has vivid – and not-so-fond memories – of 49ers linebacker Aldon Smith, who had 2.5 sacks and four quarterback hits in a performance that foreshadowed his 14-sack rookie season.

“Midway through the game everyone on our sideline was going ‘Who is this guy? This 99 is talented.’ As it turns out, he is.”